Vv. Vaishnav et al., STRUCTURAL CHARACTERIZATION OF THE GALACTOXYLOMANNAN OF CRYPTOCOCCUS-NEOFORMANS CAP67, Carbohydrate research, 306(1-2), 1998, pp. 315-330
The galactoxylomannan (GalXM) obtained from the culture supernatant of
an acapsular mutant of Cryptococcus neoformans Cap67 was purified by
Concanavalin A affinity, ion-exchange, and gel-filtration chromatograp
hies. The structure of GalXM was determined by methylation analysis an
d by 1D and 2D NMR spectroscopic studies of the intact polysaccharide
and of the oligosaccharide fragments generated by Smith degradation an
d by acetolysis. GalXM is a complex polysaccharide with an alpha-(1 --
> 6)-galactan backbone. The polysaccharide is branched at C-3 of alter
nate Gal units of the backbone. C-3 is the point of attachment of the
oligosaccharide side chains comprised of alpha-D-Man-(1 --> 3)-alpha-D
-Man-(1 --> 4)-beta-D-Gal-substituted with zero to three terminal beta
-Xyl residues as shown in the following structure: GRAPHICS (C) 1998 E
lsevier Science Ltd. All rights reserved.